package com.pks.wechat.util;

import java.security.MessageDigest;

public class MD5Util {

	private static final String hexDigits[] = {"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
	
	private static String byteArrayToHexString(byte[] b){
		StringBuffer resultSb = new StringBuffer();
		for (int i = 0; i < b.length; i++) {
			resultSb.append(byteToHexString(b[i]));
		}
		return resultSb.toString();
	}
	private static String byteToHexString(byte b){
		int n = b;
		if(n<0){
			n+=256;
		}
		int d1 = n/16;
		int d2 = n%16;
		return hexDigits[d1] + hexDigits[d2];
	}
	public static String MD5Encode(String origin,String charsetname){
		String resultString = null;
		try {
			resultString = new String(origin);
			MessageDigest md = MessageDigest.getInstance("MD5");
			if (charsetname ==null || "".equals(charsetname)) {
				resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
			}else{
				resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
			}
		} catch (Exception e) {
			// TODO: handle exception
		}
		return resultString;
	}
}
